The present disclosure relates to wireless network connections, and more specifically, to security of wireless access points.
Early computers usually communicated with each other with a wired local area network (LAN). However, due to the wide use of mobile devices (such as mobile phones, notebook computers, and personal digital assistants (PDAs)), wireless local area networks (WLANs) have evolved into one of the major ways of communication between computers. WLANs effectuate communication by means of various wireless media, such as radio signals and infrared signals.
Recent years see the rapid and across-the-board growth of portable computing. In addition to wire connection, portable computing relies heavily on a backbone network and a connected WLAN in order to access various network resources.
Among a wide variety of WLANs, IEEE 802.11 (also known as WiFi) is in wide and intensive use. IEEE 802.11b,g,n adopt an ISM (Industrial, Scientific, Medical) frequency band that ranges between 2,400 MHz and 2,483.5 MHz. The ISM frequency band is applicable to a spread spectrum system worldwide without requiring a permit.
FIG. 1 is a schematic view of WLAN authentication of IEEE 802.11. To start using a wireless local area network (WLAN), a mobile device has to perform message-based communication in three stages, namely probe request 160/probe response 164, authentication request 167/authentication response 172, and association request 176/association response 180, in their order of occurrence in time. The three stages of message-based communication are regulated by IEEE 802.11.
In the WLAN, a wireless client typically accesses, via an access point, resources available on a backbone network. The backbone network is usually a cable network (such as Ethernet), another wireless network, or a combination thereof. When an access point enables access to the resources available on a cable network, the access point includes at least a cable network interface, a bridge function, and a wireless network interface, so as to perform traffic bridging between a wireless network and the cable network.
Due to the wide use of WLANs, network security is a concern that is becoming more important. A WLAN effectuates data transmission by means of radio waves. That is to say, any wireless client within a service area covered by an access point can send data to the access point or receive data from the access point. Conventional WLANs enhance user security by means of service set identifiers (SSID), open or shared key identity authentication, Wired Equivalent Privacy (WEP) keys, media access control (MAC), Wi-Fi Protected Access (WPA), etc.
Compared with a wired local area network, although WLANs manifest greater mobility to users, WLANs attach great importance to communication security. These features of WLANs are especially important, considering that wired local area networks are less vulnerable.